Merge pull request #234 from horw/fix/leaks-file-descriptors

fix(serial.py): Pytest-embedded leaks file descriptors when used with pytest-lazy-fixture (RDT-577)

pytest-embedded-serial/tests/test_serial.py

@@ -51,3 +51,63 @@ def test_teardown_called_for_multi_dut_succeeded(dut):
 
     result = testdir.runpytest()
     result.assert_outcomes(passed=1, errors=1)
+
+
+# def test_serial_file_description_leak(testdir):
+#     testdir.makepyfile(r"""
+#         import pytest
+#         from pytest_lazyfixture import lazy_fixture
+#
+#
+#         dutHelper = None
+#
+#
+#         class DutHelper:
+#             def __init__(self):
+#                 self.duts = None
+#
+#             def setDut(self, duts):
+#                 self.duts = duts
+#
+#             def dut1(self):
+#                 return self.duts[0]
+#
+#             def dut2(self):
+#                 return self.duts[1]
+#
+#
+#         @pytest.fixture
+#         def dut_helper(dut):
+#             global dutHelper
+#             if dutHelper is None:
+#                 dutHelper = DutHelper()
+#             dutHelper.setDut(dut)
+#             return dutHelper
+#
+#
+#         @pytest.fixture
+#         def DUT1(dut_helper):
+#             return dut_helper.dut1()
+#
+#
+#         @pytest.fixture
+#         def DUT2(dut_helper):
+#             return dut_helper.dut2()
+#
+#
+#         @pytest.mark.parametrize("fixture", [lazy_fixture("DUT1"), lazy_fixture("DUT2")])
+#         @pytest.mark.parametrize("test_input", range(0, 300))
+#         def test_dummy(test_input, dut, fixture):
+#             dut[0].write("foo")
+#             assert test_input == test_input
+#
+#     """)
+#
+#     result = testdir.runpytest(
+#         '-s',
+#         '--count', 2,
+#         '--embedded-services', 'serial|serial',
+#         '--port',  '/dev/ttyUSB0|/dev/ttyUSB1',
+#         '--baud', '115200|115200'
+#     )
+#     result.assert_outcomes(passed=600)

pytest-embedded/pytest_embedded/plugin.py

@@ -2,6 +2,7 @@
 import datetime
 import dbm
 import functools
+import gc
 import importlib
 import io
 import logging
@@ -439,6 +440,16 @@ def _close_or_terminate(obj):
                 logging.debug('%s: %s', obj, str(e))
                 return  # swallow up all error
             finally:
+                referrers = gc.get_referrers(obj)
+                for _referrer in referrers:
+                    if isinstance(_referrer, list):
+                        for _i, val in enumerate(_referrer):
+                            if val is obj:
+                                _referrer[_i] = None
+                    elif isinstance(_referrer, dict):
+                        for key, value in _referrer.items():
+                            if value is obj:
+                                _referrer[key] = None
                 del obj
 
         if _COUNT == 1: